Positive psychology is now already constituted. Positive sociology is being formed. The science of language, the science of religions, the history of art are also assuming a positive form. The movement which has begun, and of which we only see the beginnings, will probably extend much further than we think. It supposes at least a provisional separation between the scientific interest and the political, moral and religious interests. Being already constituted for a considerable part of our knowledge, this separation for the remainder is still distasteful to the traditional habits of the majority of minds. We are accustomed to speculate upon physical or chemical nature with perfect disinterestedness as to the metaphysical consequences of the results which we may obtain. For we are convinced that the laws of these phenomena do not necessarily imply any consequences of this kind, or that they can be almost indifferently brought into accord with any form of metaphysics we may be pleased to adopt. What do physics, chemistry, natural philosophy _prove_, as to the destiny of man or the supreme cause of the universe? Nothing, and it does not occur to us to be surprised at it. We consider that these sciences are in accordance with their definition if they give us a knowledge of the laws of phenomena, and if this knowledge enables us within certain limits to exercise a rational and efficacious action upon nature. Are we in the same position in what concerns psychology and the moral and social sciences? This is doubtful. The very name of “moral sciences” is significant enough on this point. We cannot refrain from thinking that these sciences “prove” something outside themselves. For several of the schools of this century, psychology is still the path that leads to metaphysics. Spirituality and the immortality of the soul seem to have a direct interest in it. In a more or less conscious manner orthodox political economy has found itself “proving” the legitimacy of the modern capitalist _régime_, and has represented it as being in conformity with the immutable laws of nature. The historical materialism of Marx “proves” the necessity of collectivism. History too often serves national interests, or political parties.